1. Field of the Invention
The present invention relates to a semiconductor device socket capable of accommodating each of a plurality of semiconductor devices with different shapes and sizes in a detachable manner.
2. Description of the Related Art
For a semiconductor device mounted in an electronic equipment or the like, in order to remove potential defects in the semiconductor device at a stage before mounting, for example, burn-in tests, which are effective for excluding integrated circuits with infant mortality failures, are generally carried out via a semiconductor device socket.
A semiconductor socket made available for using for such tests is commonly referred to as an IC socket and is located on a printed wiring board (test board) as disclosed in, for example, Japanese Patent Laid-Open No. 2003-59602. As disclosed in, for example, Japanese Patent Laid-Open No. 2003-59602, the semiconductor device socket includes, as main components, a socket main body section having a semiconductor device accommodating section accommodating a semiconductor device in a detachable manner, contact pins provided in the semiconductor device accommodating section of the socket main body section and electrically connecting terminal sections of the semiconductor device to electrode sections of the printed wiring board, a cover member capable of raising and lowering with respect to the socket main body section, a latch mechanism including pressing members rotationally moved in conjunction with raising and lowering of the cover member, and an elastic member biasing the cover member in a direction in which the cover member separates from the socket main body section.
Two link mechanisms are provided respective opposite positions around the periphery of the semiconductor device accommodating section. One end of the pressing member support member constituting a part of the latch mechanism is coupled to each of the link mechanisms. A pressing member is provided at the other end of each of the pressing member support members.
When the cover member is at the uppermost position, the bias force of the elastic member acts on the pressing member support member via the cover member and the link mechanism. Thus, each pressing member is brought into contacting, under a predetermined pressure, with the common top surface of the semiconductor device placed in the semiconductor device accommodating section. This causes the terminal sections of the semiconductor device to be pressed against contact sections of the respective contact pins at a predetermined pressure.
On the other hand, if the cover member is pressed against the bias force of the elastic member so as to move closer to the socket main body section, the pressing member provided at the other end of the pressing member support member is rotationally moved to a predetermined standby position via the link mechanism so as to go away from the semiconductor device accommodating section.
In view of standardization of test facilities, square semiconductor devices externally differently sized so as to be, for example, between 10 mm and 25 mm on a side may need to be tested using a common semiconductor device socket regarding the semiconductor device socket.
When common pressing members and a common pressing member support member allow semiconductor devices with different external sizes to be pressed by the bias force of a predetermined elastic member, the length of the pressing member support member may be set such that the pressing member provided at the other end of the pressing member support member can press a semiconductor device with the minimum external size. In this case, a pressing force stronger than that corresponding to the semiconductor device with the minimum external size needs to be exerted on a semiconductor device with the maximum external size because the latter semiconductor device has more terminals than the former semiconductor device.
In case of increasing a pressing force, as shown in Japanese Patent Laid-Open No. 2005-174670, there has been proposal in which a touching portion of a pressing lever member is configured to move rotationally so as to touch to the top surface of the semiconductor device after the pressing lever member moves forward in conjunction with a lowering operation of a cover member so as to push down a pedestal which the semiconductor device is placed, under a lever ratio being changed such that the length from the support point pin of the pressing lever member to the touching portion is shorter than the distance from the support point pin to a coupling pin.